The present invention broadly relates to a new and improved construction of an apparatus for guiding a missile by means of an electromagnetic guide beam.
In its more particular aspects the present invention specifically relates to a new and improved construction of an apparatus for guiding a missile by means of an electromagnetic guide beam along a trajectory along which the missile is intended to move towards a target. In each arrangement the guide beam is encoded such that the missile receives data on the basis of which the missile can move along the desired trajectory.
In an apparatus for guiding a missile as known, for example, from U.S. Pat. No. 3,398,918, granted Aug. 27, 1968, there is generated an optical guide beam by means of a light source and the missile is guided by the optical guide beam from a launching base or site towards a target. Means are present for diverting the source guide beam such that the beam cross-section is defined by intersecting diverted beams. Further means are provided for modulating and deflecting the diverted or fanned source beam such that each diverted beam is differently modulated. The missile contains a receiver with photoelectric cells as well as control means in order to guide the missile along the guide beam towards the target.
In another apparatus of this type for guiding a missile and as known, for example, from U.S. Pat. No. 4,174,818, granted Nov. 20, 1979, a guide beam is generated by means of a light source and along a trajectory along which the missile is intended to be moved or guided. By means of a turning mask the guide beam cross-sectional area is subdivided into a checkerboard-type area or pattern. Each field sector of the checkerboard-type cross-sectional area possesses an individual code such that the receiver located in the missile can identify its location in a specific field sector of the guide beam's cross-sectional area.
It is also known to modulate an electromagnetic guide beam of an apparatus for guiding a missile. Distinctions are made between analogue and digital modulation as well as between amplitude, phase and frequency modulation so that there result six different types of modulation.
A digital frequency modulation of the guide beam in an apparatus for guiding a missile is described, for example, in U.S. Pat. No. 4,299,360, granted Nov. 10, 1981. In this known apparatus there are used two rotating encoding discs which contain through-pass openings permitting the guide beam to pass through and serving for modulating the guide beam in correspondence to their arrangement on the encoding disc.
Another known frequency modulation technique for spatially encoding the guide beam cross-section in an apparatus for guiding a missile such as known, for example, from U.S. Pat. No. 3,782,667, subdivides the guide beam into four quadrants with respect to frequency due to the use of four radiation sources each of which operates at a different frequency. The modulated radiation from the four radiation sources is combined to form a single beam having the desired spatial modulation.
It has been found that the known apparatuses can be simplified and improved.